Bushing



A1118 4, 1942. 1 J. STEVENS 2,292,248"

BUSHING FiledvNov. 8, 1940 Patented Aug. 4, 1942 BUSHING Leland J. Stevens, Baltimore, Md., assignor to Locke Insulator Corporation, Baltimore, Md., a corporation of Maryland Application November 8, 1940, Serial No. 364,939

3 Claims.

This invention relates to bushings and more particularly to bushings primarily designed for bus bar and switch support.

The principal object of the invention, generally stated, is to provide a multi-part bushing, each of the parts being provided with a closed head so that the bushing, when completed, will provide a series of separate unconnected chambers.

Still another object of the invention is to provide a multi-part bushing in which the parts are duplicates and each is provided adjacent the head with a circumferential rim or shoulder having an inwardly inclined upper face.

provide a ring I2 preferably at a slightly greater distance from the axis of the bushing than the side wall I0. rlhis concentric ring is provided with an inwardly inclined surface I3 and each ring I2 of the intermediate bushings 3 and 4 is adapted to engage a correspondingly inclined face Ed on the lower end of the superimposed unit. Each of the superimposed units is provided adjacent the outer face of the side wall Il) thereof with a lip I5 adapted to overhang the outer face I6 of the ring I2.

It will be observed that each of the units is slightly frusto-conical in form, that is the side wall of each unit and the petticoats projecting Still another object of the invention is to prol5 Outwardly IOIH the Outer Wall 3 decrease in Vide a multi-part bushing in which the parts depth or extension so that the peripheral edges are connected to each other without the inter- 0f the Dei'COatS are of the Same diameter. vention 0f metallic members, The lower unit 4 differs slightly from the in- To these and other ends the invention comtermediate unit 3 in that at its lower end the prises the various elements and combination of lip portion l5 is omitted in order that the lower elements as hereinafter set forth, end Of the unil) llmay Seat Within the metallic In the drawing the figure is a view, partially base I'I and be secured thereto by cement or in elevation and partially in vertical cross sec other means I3, the Cement Preferably undertion, snowing the assembled bushing, lying the unit and extending upwardly between Since the bushing elements are substantially the flange I9 of the base and the outer wall 8 identical in construction, differing only in minor Of the bottom portion of the unit 4. Similarly, details in respect of the upper portion of the top in the uppermost unit 2 the outer face of the bushing member and the lower portion of the ring I2 is arranged at arl angle to the aXiS of bottom bushing member, a description of one of the unit s0 as U0 DrOVde arl underut pOIton 20 these members will, it is believed, suflice for a WhiCh Seats Within a lllSO-Corleal flange 2i 0f ejear understanding of the invention, the cap member 22 and here again there is inter- The bushing I may comprise a number of posed between the cap member and the adjacent separate bushing elements and for convenience surfaces 0f the Unit 2 Cement 01 Other seurllg there has been illustrated in the accompanying means 23- drawing three bushing elements, respectively The cap members 9 of each of the units are designates, 2, 3 and 4, although it will be un- Plefelably @10H16 shaped and eXt'endiIlg at spaced derstood, of course, that additional elements, points through the rings I2 and preferably tanidentical in shape with the element 3, may be gent to the upper surface II of the dome shaped interposed between the element 3 and the ele- 'end 9 is provided a Series of drain or vent holes ment 2 or the element 4 so as to construct a busn- 40 24, the purpose and object 0f WhCh is t0 Permit ing of any desired height, moisture which may accumulate in the interior Each of the bushing elements is provided with of eaCh bushing to drain from the interior to a plurality of skirt portions 5, the undersurface the exterior thereof. of which is shaped as indicated at 6 to provide To assemble the bushings, after they are ima, drip peint 0r ring 1 so that moisture e011eet- 45 mersed in glaze and when the glaze is still moist, ing on the upper surface of the petticoat 5 will the ceramic portions of the bushings are stacked drop upon the next lower petticoat and will not and there is, therefore, formed, during the ring be carried by surface tension along the vertical operation between the surfaces I3 and I@ of each walls 8 of the bushing. Each bushing is proceramic unit, a glazed joint which serves to rigvided with a closed end 9 integral with the side 50 idly and permanently connect the units in the wallsr I0 thereof and enclosing the top of the form shown in the drawing. Owing to the inbushing and making each bushing into an inclination of the parallel surfaces I3 and I4 and dependent self contained insulating unit. to the lips which overhang the outer faces I6, as

Rising from the upper surface Il of the top previously described, all stresses transferred from 9 and concentric with the aXis of the bushing, I 55 the uppermost unit to the next succeeding unit below are inwardly directed and cause the stresses to be carried inwardly of the side wall portions of the assembled unit and there is hence no tendency on the part of one unit to slide in respect to the next succeeding unit below. I have by this means provided a unit of great strength and of ample capacity and one which is exceedingly rigid and capable of withstanding both direct loads and torsional strain to which these units are continually subjected in service. I have also provided a unit of bushings having the maximum electrical `characteristics and by strengthening each unit, that is the upper portions, by means of a dome shaped head and at the same time have providedmeans by which the air conned Within each separate unit will expand or contract without detriment to the unit or assembly and I have utilized this same means to permit condensed moisture within each unit to escape without detriment to the electrical characteristics of the assembly.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A bushing comprising a plurality of hollow units, each of which is closed'at one end, at least one of said units beingY provided at opposite ends with circular walls having inwardly and downwardly inclined surfaces, said surfaces being concentric, and fusible means for connecting said surfaces to correspondingly formed surfaces on adjacent units.

2. A bushing comprising a plurality of superimposed hollow units, each of which is closed at one end, at least one of said units being provided at opposite ends with circular walls having concentric surfaces inwardly and downwardly inclined with respect to the longitudinal axis of said unit, said unit being provided with a dome shaped head positioned within the adjacent wall, the juncture of said head and Wall of said unit being beneath the adjacent portion of said inwardly inclined surface, and fusible means for connecting said surface to a correspondingly formed surface of a superimposed unit.

3. A bushing comprising a plurality of superimposed units, at least one of said units being provided at opposite ends with circular walls having concentric surfaces formed thereon, said surfaces being inwardly and downwardly inclined with respect to the longitudinal axis of said unit, said unit being provided with a dome shaped head positioned within said adjacent circular wall, the juncture of said head and wall being spaced beneath the adjacent inwardly inclined surface, said unit being provided with a series of openings extending through the said wall, each of said openings being tangent to the upper face of said dome shaped head, and fusible means for connecting said inclined wall surface to corresponding wall surfaces formed on corresponding'adjacent portions of abutting units.

LELAND J. STEVENS. 

